Nice. I had the same problem, but in my situation, that wasn't enough. I had more than one package folder on my PC (3), and I had to find 2 of them and delete the Labs JSON file!
I overwrote the "C:\Program Files\Side Effects Software\sidefx_packages\SideFXLabs20.5\optional\labs_ocio" with default settings from houdini and worked, took me a while to figure it out, if you need, I attached below